Stuck CO2 cartridge puller

[mklotz]

A recent thread on reusing spent CO2 cartridges inspired me to use one to solve an annoying problem I sometimes encounter.

My "tack driver" pellet rifles each use two cartridges installed in a close-fitting tube under the barrel. When they are both spent and the end plug is removed the last cartridge inserted slides out easily under the influence of gravity: but, sometimes, the remaining cartridge hangs up somehow and doesn't want to slide out on its own. (I have theories of why this occurs, but that would make this too long.)

If I try to use a magnetic pickup tool (imagine a magnet on the end of a pull-out radio antenna) the magnet sticks to the steel tube before it reaches the cartridge and, even if it did, it would be off center which would mean the pulling force would be off center.

What's needed is a device that would hold the magnet centered in the tube as it's slid down to latch on to the stuck cartridge.

I took a spent cartridge and turned a flat on the hemispherical end. A short length of wooden dowel was epoxied to this flat and a neodymium button magnet epoxied to the dowel. Since the spent cartridge fits nicely in the tube, the magnet will be held on the tube centerline and can't latch onto the walls - hence the use of the spent cartridge. The wooden standoff dowel prevents the magnet from magnetizing the cartridge.

There was just enough meat left in the hole in the other end to tap it 5-44, the thread on the Hoppe's airgun cleaning rods. The rod gives me plenty of reach to the stuck cartridge.

I haven't used it in anger yet but I'm fairly sure it will work. The stuck cartridges aren't badly stuck; once the magnet locks on a gentle pull on the cleaning rod will break it free.